EarthBound (Mother 2) · Super Nintendo (SNES) · 1995
EarthBound contains hidden code that detects pirated copies of the game and punishes players with escalating difficulty before deleting all save data at the final boss.
HAL Laboratory and Nintendo embedded multiple layers of anti-piracy detection in EarthBound's cartridge. A pirated copy would first show an error screen early in the game. If that was bypassed, the game would continue but with dramatically increased enemy encounter rates — potentially tripling the frequency of random battles. Players who persisted through this to the final boss, Giygas, would find the boss fight impossible to complete: the piracy detection triggers a loop near the end of the encounter. Upon what would be the final blow, the game freezes and then reboots, deleting all save files in the process. The multi-stage punishment — starting subtle and ending catastrophic — was considered unusually sophisticated for the era and has been studied as a model of game-integrated DRM design.
This is not meant to be found — it triggers automatically on pirated ROMs. On a legitimate cartridge, the anti-piracy code is dormant. The detection checks for specific hardware signatures present in illegal reproduction cartridges and absent on official Nintendo PCBs.